Greenhouse Hothouse Firehouse

A scientific paper recently published in the Proceedings of the National Academy of Sciences (PNAS) is getting a lot of attention. Written in the dry style of systems analysis—and throughout the text referring to the planet as the ‘Earth System’, it nevertheless brilliantly manages to present the looming dangers of extreme climate change in a way that has powerfully resonated with many people. People who are worried about climate change, but aren’t exactly sure what the future holds, how bad it’s going to get, and how to avoid being dragged in that direction. You can access the paper here.

Into the hothouse

‘Hothouse Earth’ is where we are all headed. And those two words, after the record heat waves and raging wildfires we have witnessed this year, conjure up images that most of us can fully comprehend. We can almost feel the heat.

Not only that, the authors have created a simple graphic which although dimensioned in the metrics of time, space, and temperature, is easily understandable. The Earth is a ball gently rolling down a slope of increasing global temperatures. Two pathways are available to us. But only one can be chosen.

The pathway of least resistance is the one we are on now. The one that leads to the hothouse.

The diagram shown below perfectly captures the concept.

We know that actions taken so far to reduce global emissions of greenhouse gases are hopelessly inadequate. Atmospheric concentrations of carbon dioxide and methane—the most damaging of the greenhouse gases that are responsible for global warming—continue to increase every year. There are no signs that the warming trend is slowing.